Youngs Modulus Flashcards
Why is the ruler stood up
Reduces parallax error
Accurately read vernier scale
Why does the wire start extending at an increasing rate
Gone past the elastic limit
No longer straight line graph
What does the vernier scale moving represent
Extension
Stress strain graph
Stress y
Strain x
Gradient is youngs modulus
Area is the strain energy per unit volume
How do you measure the cross sectional area of the wire
Micrometer
Measures diameter
Random error, wire isn’t uniform diameter
Take 5 parts along wire and average
Two safety issues
Mass increasing increases the chance of the knot coming undone or string snapping and masses falling
So don’t have feet below
Wire snaps and pings up into eyes
So wear safety goggles
Assumption
In order to consider the stress we’ve taken the area to be constant
So assume the wire doesn’t stretch enough to make the wire thinner
